This invention relates to switching arrangements for controlling the flow of a relatively high current to a load at a remote location by means of a control circuit using low level current. More particularly, it relates to a control circuit to which a number of control switches can be connected to control switching of current to the load independently of each other and in which provision is made to indicate the on/off status of the load.
Using present day house wiring techniques, the operation of a current consuming device at a fixed location, such as a lamp for illuminating a stairway, can be controlled from two or more switches placed at locations which may be remote from the current consuming device. A typical stairway lighting circuit has two single-pole double-throw switches which are located at the top and bottom of the stairs. The switches which are interconnected by standard electric wiring so that the current flowing to the stairway lights can be directed to the lamp via one or the other of two control wires. (The return flow of current from the lamp does not go through through the switches). In this arrangement, the flow of current is directed to the pole of one switch and travels, depending upon the position of the pole, via either one of the two wires to the second switch. At the second switch, either of the two wires can be connected by the switch pole to the load. When both switches are connected to the same control wire, current flows though the switches to the load. By switching either of the two switches into connection with the other lead, current flow will cease, but can be reestablished at either switch. So called three-way or multi-way systems of the type just described require the use of multiple switches and wiriing which must be able to handle the full load current and voltages.
It is an object of the present invention to provide a multi-way switch system which is capable of operation from a multiplicity of locations and which permits the use of control circuitry operating at low current and voltages.
It is another object of the invention to provide a multi-way control system which is capable of reporting the on-off status of the load device at any or all of the remote control locations.
It is an additional object of the invention to provide a multi-way switch system in which the wiring is simplified so that only two control conductors are required to connect one or a plurality of switch circuits for control of the same load circuit and which, at the same time, affords status reports as aforesaid.